Some platinum complexes represented by cisplatin [namely, cis-diamminedichloro platinum (II)] show a prominent antitumor effect, and are applied as chemotherapeutic agents for malignant tumors to various disease cases.
Cisplatin, however, has a very strong toxicity such as nephrotoxicity, and therefore, the remedial affect of cisplatin is hindered by this strong toxicity.
Second generation platinum complexes represented by platinum (II) cis-diammine-1,1-cyclobutanedicarboxylate, carboplatin, were developed, and although the nephrotoxicity is moderated in these platinum complexes, the antitumor activity is lower than that of cisplatin.
Accordingly, the development of a chemotherapeutic agent having a toxicity lower than those of the conventional platinum complexes, and a higher antitumor effect, is desired.